Components of grain yield in wheat

Abstract

Between 1972 and 1976 a series of field experiments were conducted to investigate the factors limiting grain yield in
wheat (Triticum aestivum L). Spike population restricted yield
when it was below about 500 spikes/m² but once it exceeded 700/m²
grain yield declined due to a reduction in the number of grains
per spikelet. Irrigation, high sowing rate, and nitrogen
fertiliser generally increased spike number but the effects on the
number of grains/spikelet were variable, apparently depending on
processes related to leaf area index.
The semi-dwarf Karamu outyielded New Zealand wheats when
spring-sown because it produced more spikelets/spike and more grains/
spikelet than the other cultivars. The superior grain set of
Karamu was because more of the distal florets within each spikelet
produced grain than in the other cultivars.
The results are discussed in relation to cultural practices
and plant breeding.... [Show full abstract]